Stenciling machine



May 19, 1964 T. G. HARRIS l-:TAL

STENCILING MACHINE Filed April 2, 1965 INVENTOR THOMAS G- HARRIS ELMER J. LANDIS United States Patent "ice 3,133,312 STENClLING MACHENE Thomas G. Harris, East Hernpiieid Township, Lancaster County, and Eimer Il. Landis,r Manheim Township,

Lancaster County, Pa., assignors to Armstrong Cork Company, Lancaster, Pa., a corporation ot Pennsylvania Filed Apr. 2, i963, Ser. No. 27l,tl37

4 Ciaims. (Cl. 18--5) .This invention relates to an improvement in a stenciiing machine for the manufacture of inlaid linoleum, inlaid thermoplastic resin surface coverings, and the like. It is concerned moreparticularly with a specially constructed stencil plate for use in conjunction with a brush for removing inlaying composition.

In :stenciling machines for the manufacture of inlaid surface coverings, a metal stencil is provided having openings therein through which granulated inlaying compositions are strickled. A metal plate is used to form the stencil and the openings made in the metal plate correspond to the design of the inlaying compositionsbeing laid up by the particular stencil. The stencil openings are generally provided with bridging wires which extend across the stencil openings and which are attached to the stencil plate to provide a supporting structure for the solid portions of the stencil disposed between the Openings. Berger Patent 2,241,051 discloses a stenciling machine of the type referred to.

In forming complex designs with stenciling machines of the type referred to, a series of stenciling machines are used, some patterns requiring as many as seven or more stencils in series to complete the inlaid pattern on an appropriate backing material. The stencil units include a conventional strickler mechanism such as disclosed in the Berger patent referred to above, and include means for feeding granulated linoleumcompositions or the like onto the supporting backing which is received on a Slat-type conveyor positioned below the stencil.

In forming inlaid plastic surface coverings of the typel with which this invention is concerned, a given pattern is laid up by the iirst stencil by positioning the supporting backing beneath the stencil, lowering the stenciling unit on appropriate side supports, depositing the inlaying composition through the stencil openings by strickling means onto the backing after which the stenciling unit is raised and the backing is moved by the conveyor to bring a fresh area of the backing into position and to bring the backing having the molding inlay composition deposited thereon to the next station. The color feeding machines withthe stencils in place, or the stencil units, are set at a specified height above the table. When a series of stencil units are used to form a design, it becomes irnportant for each successive stencil unit to feed a given thickness through the stencil openings onto the backing.

' As shown in FIGURE 4 of the Berger reference, the stenciling machines of the prior art have been designed to lay up the inlaying composition to a depth which cornes to the top of the stencil openings. When this is done, succeeding layups result in a greater amount of material being required to iill the openings of the stencil. This is so because each succeeding layup becomes engaged at a level which is above the original thickness setting and which is equivalent to the thickness of the stencil plate. Thus the lowering of the next stencil to the originally determined thickness is prevented by the height of color, compressed slightly, previously laid up. When brushes are used to sweep the inlay composition from the openings, the reinforcement wires of the stencil openings, shown in FIGURE 4 of the Berge patent, have prevented the brushes from sweeping the composition comii Patented May 19, 1964 pletely out of the opening and the removal of the inlay composition has been further complicated by the inability of the brushes to completely sweep the area immediately adjacent to the solid portion of the stencil parallel to the brush shaft. This phenomenon is particularly pronounced when a stencil plate having narrow openings is used. The above-enumerated difficulties are generally referred` to by the expression pyramiding. When the designs laid up upon the backing are pressed, the ridges, caused by the pyramiding, collapse or spew and the highest layup accepts full pressure of the press. This layup flows, or liquees and ows, bringing the second highest layup into play.

The primary object of this invention is to provide a stenciling unit for the manufacture of molded linoleum and similar productswith means for laying up design elements of a desired uniform thickness through the stencil openings. yAn ancillary object of this invention is to i provide a stenciling unitvwhich will eliminate the abovedescribed so-called pyramiding problems.

Thme and other objects of the invention will be clear from the following description of an embodiment of the invention which will be given in conjunction with the attached drawing, in which: Y

FiGURE l is a side elevation of a typical strickling unit,

FIGURE 2 is a diagrammatic view illustrating the construction of the stencil plate in accordance with the invention and the manner in which the rotating brush functions as it distributes the color through the stencils; and

tion or the like is fed onto a supporting backing 4 which is received on a conveyor 5 which is moved intermittently below the stencil 2 to bring fresh areas of the bacing 4 into position to receive inlays of linoleum composition or the like to be deposited through the openings in the stencil. l

By way of example, the granulated linoleum composition is received within a hopper 6, and a veined feeder deposits a measured amountof composition into the path of a plurality of strickling and compressing blades mounted on strickler carriages 7 which are secured to an endless chain carrier. The blades serve, when moved over the stencil 2, to distribute linoleum composiiton deposited in their path by the veined feeder over the stencil and through the stencil openings 3 onto the backing 4 and -to compress the granulated material to a slight degree.

The stenciling unit-is mounted on side railsS and 9 which are arranged to be raised upon completion of each stenciling cycle and to be lowered again after the backing 4 has been moved by conveyor 5 to bring a fresh area into position for the reception of inlaying composition. A'table 10 supports the backing@ and the. slat conveyor 5.

Behind the series of strickling and compressing blades mounted on strickler carriages, a rotating brush Ill and a motor 12, for driving the rotating brush, are secured and set to remove the amount of inlay'composition in excess of that required to ll the open stencil areas below the bottom surface of the stencil plate. A more complete description of the stenciling unit, including the means for activating and driving the rotating brush and the means for moving the stricklers and brush over the stencil plate, may be had by reference to Berger, U.S. Patent 2,241,051.

With reference to FIGURES 2 and 3, where 'views of the stencil plate showing the `openings therein are illustrated in greater detail, the openings 3 in the stencil plate 2 are tapered back 1/s" from the edge of the openings and are eut to .008" tof the bottom of the stencil at the opening edge creating an tangle of 23.5 kfrom the surface of the stencil plate. 'I'lie wires 113 tand 14, across which the brush 11 travels, are used to hold the stencil together and to limit the depth to which the brush can sweep. They are placed at the very bottom of the stencil plate so that the brush 11 can remove all the inlaying composition all the way down to the bottom of the stencil opening. When the wires across the 'stencil opening are placed in two directions to add strength to the .over-all structure of the stencil they lare placed substantially at right angles to one another. Where it is necessary to have wires in both directions, the wires 13 runnin-g perpendicular to the direction of brush travel rare placed at the very bottom of the stencil and the wires 14 running with the direction -of the brush travel immediately above them. Previously laid up inlaying composition -is shown at 16. The di-rection of brush travel is illustrated by the yarrow in lFIGURE 3.

I-n operation, the discharged inlaying composition is spread tonto `the stencil and through the openings therein by means `of the scraper blades attached to the striclcler carriages 7. The series of scraper blades are gener-ally arranged at decreasing tangles with respect Ito the 4stencil plate and yare provided to torce the composition to completely till the stencil openings. 'I'he blades by reason of their position `with respect to the surface of the stencil plate 2 further serve to ycompress to a limited extent the composition in the stencil openings 3. Next the brush 11 behind the scraper blades, as shown lin FGU'RE 2, removes ltall of the excess composition 15 remaining on the surface of the stencil zand yadditionally the bristles of the brush enter into the stencil yopenings in the plate to remove `all of the comopsition to the bottom of the openings, the depth to which the brush can sweep being limited by the wires 13 at the bottom of the stencil plate and `across which the brush ftnavels. Models 17 secured to the bottom vof the stencil 2 serve to confine the inlaying composition to the desired design on the backing 4.

In order to insure that the inlaying composition is not removed below the bottom ,of the stencil openings, the wires 13 placed perpendicular to the direction of brush travel at the rvery bottom :of the stencil are at internals of between a minimum of l yand :a maximum of 5/s. The Wires placed substantially parallel to the direction of brush travel, `of course, do not limit the depth to which the bristles enter the stencil openings and their spacing is thus not critical to the functioning of the stenciling machine.

We have found that the machines function in the desired manner when the angle at which the sides of the opening are tapered is `an angle of from 213.5 to 43.5 from the upper surface of the plate.

The improvements in the stenciling machines of this invention have resulted in a number of benets accruing from the elimination of pynamiding during the manufacture of inlaid surface coverings. rThus, in manufacturing, iewer pickups occur; that is, the lowering of the stencil plate no longer results in intimate contact of the stencil plate with the pyramided portions lof previously inlaid design and thus reduces the tendency of the stencil plates to pick up previously laid inlay composition. This results in considerably improved yields of merchandisable product. The products laid up with the stenciling machines of this invention have la more uniform gauge so that the pressing cycle imparts a more uniform application 0f heat `and pressure [with better Iover-'all properties in the iinal product as well las longer press pad life in the equipment. Because of the more uniform gauge, the removal of release paper is greatly improved and higher temperatures may be used during the consolidation cycle Cil t resulting in improved properties in the surface coverings and shorter consolidation cycles.` With the substantial elimination of spew (caused b y pyramiding, improvements in registering embossing are achieved Ias well las the elimination [of repeat marks in the surface coverings and less distortion in the product. VBy `achieving a more uniform gauge, improved surface `coverings of lower `gauges have been made possible.

This invention has also resulted in surface coverings of greatly improved saleability. This is yparticularly true lof inlaid surface coverings formed tfrom the thermoplastic vinyl resin inlaying compositions as Ithe more uniform gauge of layup has resulted in less Waviness in the nally consolidated product with resultant improved visual characteristics. With vinyls, the problem fof pyramiding in inlaid designs becomes more pronounced `insofar as the vinyl inlaying compositions have less compressibility than the standard inlaying `compositions formed of linoleum resins. Of course, the more uniform gauge results in the same type of improvements in inlaid linoleum products. Because of the greater uniformity of products produced using the improved stenciling machines of this invention, greatly improved installations of the surface coverings are [achieved through the improved pattern matching with attendant better seams. The more uniform gauge results in a surface covering having better maintenance characteristics such as improved :and easier waxing characteristics.

The table set forth below shows the improvement in gauge of molded inlaid surface coverings realized in the practice of this invention. Two surface coverings were made using a `granular thermoplastic vinyl resin -inlaying composition for forming identical inlay `designs using Ia yseven stencil layup. Surf-ace covering A was laid 'up with stenoiling machines embodying this invention `and surface covering B was laid up using stenciling machines of the type disclosed in Berger U.S. Patent 2,241,051. Both surface coverings were laid up starting with the same settings between the stencil plate and the felt backing tand identical consolidating and linishing steps were used in forming the finished surface coverings.

Table Surface Covering A B .000l to .082. Average Gauge 068 W'e claim:

l. A stcnciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled onto a suitable backing, said openings having the sides thereof tapered at an angle of from about 13.5 to 43.5 from the upper surface of the stencil plate to substantially the bottom thereof, means movable over the stencil plate for strickling an excess amount of granulated inlaying composition over the upper surface of the stencil plate and into the openings to fill said openings with granulated inlaying composition, a brush movable over said stencil plate behind said strickling means for removing excess inlaying composition from the surface of the stencil plate and from the openings thercin, and means for limiting the depth to which the brush can sweep to substantially the bottom surface of said plate.

2. A stenciling machine as defined in claim l in which the means for limiting the depth to which vthe brush can sweep comprises a plurality of wires running substantially perpendicular to the direction of brush travel and secured across the openings in said stencil plate at substantially the bottom thereof.

3. A stenciling machine as defined in claim 2 in which a plurality of additional bridging wires are secured imwill mediately over the brush limiting Wires across the stencil openings in a direction substantially parallel to the direction of brush travel.

4. A stenciling machine including a stencil plate having openings through which granulated inlaying composition may be strickled onto a suitable backing, said opening having the sides thereof tapered at an angle of from about 13.5 to 43.5 from the upper surface of the stencil plate to substantially the bottom thereof, means movable over the stencil plate for strickling an excess amount of granulated inlaying composition over the upper surface of the stencil plate and into the openings to ll said openings with granulated inlaying composition, a rotating brush, including means for driving the brush, movable over said stencil plate behind said strickling means for removing excess inlaying composition from the surface of the stencil plate, and a plurality of wires running substantially perpendicular to the direction of brush travel secured across the openings in said stencil plate at substantially the bottom thereof.

Berger May 6, 1941 Leng Sept. 28, 1954 

1. A STENCILING MACHINE INCLUDING A STENCIL PLATE HAVING OPENINGS THEREIN THROUGH WHICH GRANULATED INLAYING COMPOSITION MAY BE STRICKLED ONTO A SUITABLE BACKING, SAID OPENINGS HAVING THE SIDES THEREOF TAPERED AT AN ANGLE OF FROM ABOUT 13.5* TO 43.5* FROM THE UPPER SURFACE OF THE STENCIL PLATE TO SUBSTANTIALLY THE BOTTOM THEREOF, MEANS MOVABLE OVER THE STENCIL PLATE FOR STRICKLING AN EXCESS AMOUNT OF GRANULATED INLAYING COMPOSITION OVER THE UPPER SURFACE OF THE STENCIL PLATE AND INTO THE OPENINGS TO FILL SAID OPENINGS WITH GRANULATED INLAYING COMPOSITION, A BRUSH MOVABLE OVER SAID STENCIL PLATE BEHIND SAID STRICKLING MEANS FOR REMOVING EXCESS INLAYING COMPOSITION FROM THE SURFACE OF THE STENCIL PLATE AND FROM THE OPENINGS THEREIN, AND MEANS FOR LIMITING THE DEPTH TO WHICH THE BRUSH CAN SWEEP TO SUBSTANTIALLY THE BOTTOM SURFACE OF SAID PLATE. 